A so-called liquid crystal display (LCD) is known to use a backlight. The brightness of a sub-pixel may for example be controlled by selecting an orientation of a liquid crystal material, which in turn determines the transmissivity of the liquid crystal material for light from the backlight.
In a pixel with red, green and blue sub-pixels, each sub-pixel may have a corresponding colour filter, for example a red, green and blue colour filter. However, for each sub-pixel, this approach can result in a significant loss of light between the light output by the backlight and the light output from the colour filter.
It is known to use luminescent materials in a display device to output light, possibly in conjunction with a backlight. Such display devices are often complex in design and manufacture, requiring for example careful selection of different luminescent materials which are compatible with each other and which also output the required sub-pixel colours.
It is desirable to simplify a display device.